The present invention relates to video display systems, and more particularly to video display systems and methods for providing automatic display of electronic manufacturing drawings during assembly of elongated workpieces.
The manufacture and assembly of elongated workpieces, such as floorbeam assemblies for a commercial aircraft, is a labor-intensive and tedious operation. For example, commercial aircraft floorbeam assemblies typically vary in length from 14 to 23 feet long, and can have over 150 assembly configurations for a single aircraft. Oftentimes a single mechanic is required to install various subassemblies or attachments to the floorbeam.
To assist the mechanic in assembling the floorbeam, visual aids and instructions are provided in the form of assembly maps or drawings. Typically, the floorbeam is set up at the mechanic""s workstation or bench, and the assembly drawings are spread out behind the bench so that the mechanic can refer to the drawings during assembly. In particular, due to the array of different floorbeam assemblies for the mechanic (and subsequent inspection teams) and the complexity of each floorbeam, full-scale drawings are used so that the mechanic can constantly refer to the drawings while working at any point along the floorbeam. As shown in FIG. 1, a floorbeam drawing typically consists of three or more large Mylar sheets 110 that are taped together and marked up with comments and warnings. Therefore, the full-scale assembly drawings for each floorbeam 120 must be rolled up, stored, and a new full-scale assembly drawing must be retrieved and spread out across the back of the workstation 122 before assembling the next floorbeam or other workpiece. To make matters worse, working inventory is usually minimized so that identical floorbeams are not built consecutively. Thus, the mechanic wastes valuable time retrieving and storing assembly drawings for each floorbeam assembly.
Moreover, conventional Mylar assembly drawings can cause compliance issues with governing bodies. In particular, conventional drawings are often considered xe2x80x9cuncontrolledxe2x80x9d documents, since changes can be made to the drawings without proper verification. Such changes can lead to audit failures performed by governing bodies, such as the Federal Aviation Administration (FAA) or the International Organization for Standardization (ISO). In addition, conventional drawings must be kept current, replaced when worn or damaged, and the notes and mark-ups must be transferred to any replacement drawings.
Another assembly method that also suffers from the use of conventional assembly drawings is the moving assembly line. Previously, assembly methods using moving lines to assemble long, complex assemblies were hampered by the inability to display the assembly or manufacturing drawing of the part as it moved past the assembly mechanic. The handling drawbacks of repositioning the drawing as the workpiece moved past the mechanic are obvious. Moreover, it would be highly impractical, if not impossible, to assemble more than one assembly configuration on a moving assembly line where the mechanic would be required to retrieve a new drawing for each assembly configuration.
To aid in workpiece assembly, systems have been developed that project assembly drawings of the workpiece onto the actual surface of the workpiece via one or more fixed laser projectors. The laser projectors are typically set about ten feet above the workpiece in order to maximize the coverage of laser projections over the workpiece. However, as the distance between the workpiece and the laser projectors increases, the projected drawings can become distorted as the lasers intersect the workpiece at oblique angles at areas not directly under the lasers. Further distortions can be caused if the lasers encounter surface irregularities on the workpiece, which increase the level of distortion as the distance between the workpiece and projectors increases. Optic devices and software can be used to correct the distortions, but at a significant cost.
Another conventional system employs a virtual reality system that includes a device for sensing the position of a wearer""s head (i.e., the direction of view) and a head-mounted, transparent viewing screen for displaying a corresponding view. In the virtual reality or head-mounted display systems, however, the image is determined by the wearer""s head angular orientation in relation to the workpiece, which can disorient the wearer. In addition, these systems do not provide any view other than true scale, as magnifying the scale (zooming in) would also disorient the wearer.
The present invention is directed to a visual aid apparatus for providing assembly instructions of a workpiece. Advantageously, the apparatus of the present invention eliminates the hardcopy drawings and associated problems of conventional assembly systems by employing a computer, monitor, and a position-sensing device that determine the position of the monitor relative to the workpiece and determine assembly instructions corresponding to the workpiece at the location of the monitor. The assembly instructions are then displayed on the monitor, which can be moved along the workpiece displaying corresponding assembly instructions as the monitor moves. Thus, the assembly instructions are maintained by the computer of the present invention and displayed by the monitor, which thereby greatly simplifies the workpiece assembly process.
In particular, a visual aid apparatus for providing assembly instructions of a workpiece according to one embodiment of the present invention comprises a computer having a memory device and an elongated rail extending lengthwise proximate the workpiece. A monitor is movably mounted to the rail and operatively connected to the computer, such as wirelessly connected or hardwired thereto. The monitor is preferably a color monitor. In addition, storage bins for fasteners and the like may also be operatively attached to the monitor so that the monitor and bins can move along the rail. Preferably, the monitor and bins move together, although the bins could move separately from the monitor.
The visual aid apparatus of the present invention also includes a position-sensing device that is attached to the monitor. The position-sensing device is capable of determining the position of the monitor relative to the workpiece and sending the relative position to the computer. In one embodiment, the position-sensing device includes a timing belt and a timing belt pulley that move relative to the monitor such that the position of the monitor can be determined by a corresponding rotational position of the timing belt pulley. The position-sensing device may include alternatively a laser range finder, linear transducer, or cable encoder in order to determine the position of the monitor relative to the workpiece. The monitor is also movable along the rail, and the computer is capable of refreshing the monitor to display the corresponding assembly instructions for the workpiece while the monitor is moving.
The computer is capable of determining assembly instructions corresponding to the relative position of the monitor and providing the assembly instructions for display on the monitor. In one embodiment, the assembly instructions are in color, wherein similar components of the workpiece are depicted in a similar color. In addition, warnings or alerts can be depicted in another color to alert the operator to ambiguous or important information in the assembly instructions. In one embodiment, the assembly instructions include an original assembly drawing and at least one mark-up instruction that provides at least one revision to the original assembly drawing.
Thus, the visual aid apparatus of the present invention eliminates the cumbersome hardcopy drawings used in conventional assemblies. Advantageously, the apparatus and methods of the present invention improve the safety, document control, and efficiency of the assembly process. No longer are mechanics and operators required to roll up cumbersome drawing sheets for storage, only to unroll the drawings again for subsequent use. By contrast, the assembly instructions of the present invention are maintained in the computer such that they can be quickly and easily recalled and updated.